Background:
Flight attendants at Alaska Airlines reported health symptoms after the introduction of new uniforms in 2011. The airline replaced the uniforms in 2014 without acknowledging harm. To understand possible uniform-related health effects, we analyzed self-reported health symptoms in crew who participated in the Harvard Flight Attendant Health Study between 2007 and 2015, the period before, during, and after the introduction of new uniforms.Methods:
We calculated a standardized prevalence of respiratory, dermatological and allergic symptoms at baseline, as well as during and after uniform changes in 684 flight attendants with a varying number of surveys completed across each time point. We used Generalized Estimating Equations (GEE) to model the association between symptoms at baseline versus the exposure period after adjusting for age, gender and smoking status and weighting respondents for the likelihood of attrition over the course of the study period.Results:
We found the following symptom prevalence (per 100) increased after the introduction of new uniforms: multiple chemical sensitivity (10 vs 5), itchy/irritated skin (25 vs 13), rash/hives (23 vs 13), itchy eyes (24 vs 14), blurred vision (14 vs 6), sinus congestion (28 vs 24), ear pain (15 vs 12), sore throat (9 vs 5), cough (17 vs 7), hoarseness/loss of voice (12 vs 3), and shortness of breath (8 vs 3). The odds of several symptoms significantly increased compared to baseline after adjusting for potential confounders.

Conclusions:
This study found a relationship between health complaints and the introduction of new uniforms in this longitudinal occupational cohort.